July 2014

July 13, 2014

"People of a political kidney never can, never will at any time acknowledge the slightest possibility that they might be mistaken. That way lies the imminent crumbling of dogma, and the freakish implication that those holding opposite views could be, after all, tolerable, decent, even respectable." - Brooke McEldowney

Oliver Cromwell is said to have made the following plea to certain of his opponents: "I beseech thee in the bowels of Christ, consider that ye may be wrong."

Indisputably, it is always a possibility that you and/or I may now and then be wrong about something. Over the long haul, being wrong at one time or another is a certainty.

That's why I so enjoyed an old Peanuts cartoon by Charles Schultz where Lucy tells one of the other children that, yes, she remembered that she had been wrong once. It was back in 1958 when she thought she was wrong about something, but then realized that she'd been wrong about thinking that she had once been wrong.

Then we have Dr. Stephen Hawking who rather recently announced himself as having been wrong in some of his prior writings about astro-physics and black holes, but who later thought things through and corrected himself.

Talk about unimpeachable intellectual honesty!! There's no false pride in that man which is the key, actually. It all does come down to intellectual honesty.

I would rather put my trust in somebody who admits to having human frailties, to put my trust in someone who doesn't see himself as intrinsically above the common crowd which would certainly exclude that arrogant mathematician I once encountered.

Conversely, nobody can be wrong all of the time either. To achieve that would be to have arrived at a state of perfection. Since no mortal being is perfect, each of us has to be right about something at least sometime.

In either case, we are talking about human frailty and human limitations. I have too often heard from this or that blowhard, often in high dudgeon, spouting off phrases like "...but YOU SAID that ....".

July 12, 2014

I have been collecting daily Newsday weather pages, weather.com wind and weather maps, and Google weather reports for San Francisco, San Diego, and Yuma AZ. The latter give 24-hour wind speed and direction predictions for these cities. Newsday often reports fog for San Francisco, and the weather reports usually report mild temperatures and over 60% humidity. The wind direction is often from the west, so that moisture from the Bay area would be transported inland. But the Sacramento and Imperial Valleys do not get sufficient rainfall and require irrigation from the Colorado River reservoir system. I originally thought that solar heated evaporator rafts in San Francisco Bay would increase the humidity enough to produce rain, but readily accessible websites and references indicate that there is already enough water vapor in the air and evaporator rafts will not solve the drought problem.

What seems to be needed is some means of causing the moist air to rise, expand, cool, condense the vapor, and grow water droplets large enough to precipitate. Wind flow over mountains to the East could produce some orographic precipitation, but not much seems to be happening. Convection caused by a hot spot on the surface might cause a sufficient volume of moist air to rise and produce useful rain. Analyses of convection over a hot spot have been published and I will attempt to understand them and estimate how much hot spot area is required.

There are several airports around the Bay area, but Google Earth shows them to be bright, and therefore not sufficiently solar heated to induce convection. It is interesting that small areas of runway where aircraft touch down have black skid marks that would act as good solar absorbers. But these areas are small, and are cleaned off regularly to improve traction. Furthermore, the concrete has large thermal mass and the temperature rises slowly. This delays convection until late in the day and reduces the effectiveness.

The wooden evaporator rafts discussed in previous blog posts could be deployed upside down so that the flat black plates would present a dry surface to the sun. They would be supported by the buoyancy of the wood cross pieces, augmented by one or two additional cross pieces to increase the flotation height. The wood plates would have low thermal mass and would heat rapidly, starting convection early in the day. Similar mats of black wood plates could be installed on land areas that would not interfere with aircraft or other operations.

So, in the San Francisco Bay area, the analysis task shifts from evaporation rate to convection over a hot spot on the surface. I hope I can make some progress.

July 03, 2014

You know about the recent terrible story of a toddler who died from overheating in a closed up car. I would like to offer two related personal anecdotes.

Years ago, this fellow whom I once knew owned a 1962 Mercury Comet. It was an unimposing small sedan. It's color was black. For some reason, he had mounted a circular dial thermometer on the dashboard. The thermometer's maximum calibration mark was 150°F.

One summer day, with that car parked in direct sunlight, with the doors shut and with all of the windows rolled up, that thermometer dial got pegged. The passenger compartment temperature had reached at least that maximum of 150°F. It may have been hotter in there. Had there been anyone inside that car, I don't think the circumstance would have been survivable.

In another situation, I and my wife once lived in an apartment on the second floor of a flat roofed row house in Canarsie, in Brooklyn. It was on East 87th Street near the corner of Bedell Lane. If you just happen to be familiar with that area, you'll appreciate what kind of home it was.

At the time, we had a decorative candle on our dining room table. It was a rather large candle, about two inches across, and it was mounted on a special holding dish.

One summer, we took a two-week vacation and when we got back, we discovered that the candle had melted. What had been an upright wax cylinder had become a shapeless wax puddle. I don't know what temperature our apartment had gotten up to, but it had to be really high to have melted the candle down so completely..

The lesson is clear.

Never, absolutely never leave a child or someone elderly or someone ill and infirm or anybody alone in any environment that is even remotely akin to these two.